1. Field of the Invention
The present invention relates to a terminal connecting device for very simply making connection to the terminal of, for example, a car battery.
2. Description of the Related Art
Conventionally, these kinds of terminal connecting devices for a car battery are arranged such that, for example, a connecting member formed substantially to an ohm-character shape is disposed to surround a battery terminal and the end portions of the connecting member are tightened by bolts and nuts. Then, a cable end is connected to the male screw portion projecting from the connecting member and tightened by a butterfly nut. At this time, a connecting terminal having a through hole is connected to the cable end by caulking, welding or the like and the through hole of the connecting terminal is engaged with the above male screw portion.
Further, a cable is fixed by making use of a tightening action of bolt and nut in such a manner that a cable end is inserted into the inserting portion of an opening defined to a bolt itself and the cable is fixed by being strongly tightened by a nut tightened to the screw portion of the bolt. For example, refer to the specification of Japanese Utility Model Registration No. 25547, Japanese Utility Model Publication Nos. Sho 2-5180, Sho 35-26653, Sho 37-19755 and the like, and further to Japanese Utility Model Publication No. Hei 3-13969 proposed by the applicant.
Nevertheless, according to the above conventional connecting devices, since a connecting terminal is connected to a cable end beforehand, a thin plate-shaped electric conductive sheet terminal cut substantially to a flat T-shape must be prepared and the opposite ends thereof must be caulked to bundle a cable wire and connected thereto. Moreover, in a connecting job, the connecting member must be connected to a battery terminal by bolt and nut and further butterfly nuts must be tightened to the male screw portion of the connecting terminal at two positions. This job is very time-consuming and the arrangement of the connecting devices is complex and expensive.
Further, since the conventionally proposed structures tightened by bolt and nut disclosed in the above publications have a bolt with a hole into which a cable is inserted, unless the twisted thin wires of a cable end are brought together (in the case that the cable is composed of the twisted thin wires), the cable cannot be smoothly inserted into the hole and thus a connecting job is time-consuming. In addition to the above, since various small parts are assembled for the wire to be connected and fixed, the structures are complex and expensive and the handling thereof is very troublesome.
Further, since the terminal connecting device disclosed in Japanese Utility Model Publication No. Hei 3-13969 proposed by the applicant has a bolt having a male screw portion to which a groove-shaped inserting portion is defined and this portion is inclined with respect to the axial center of the bolt, it is found that a cable can be easily inserted into the inserting portion and stably fixed under pressure, whereas the cable does not have a sufficient strength and may be broken by an external impact or the like. Further, in addition to the above problem, when a strand cable composed of thin wires is inserted into the inserting portion, these thin wires may be caught by the opening edge of the inserting portion and not be smoothly inserted thereinto.
Thus, taking the above into consideration, an object of the present invention is to provide a terminal connecting device having a simple structure and capable of being easily mounted, and by use of which not only can the cable be easily inserted and held so that working efficiency can be improved, but also the cable can be stably fixed with sufficient strength.